Doubling down on a repeated line of attack against Marco Rubio, Democratic U.S. Senate candidate Patrick Murphy wants the Republican incumbent to now sign a pledge committing to serve a full six-year term, if re-elected in November.
Rubio has been noncommittal on the idea -- leading Murphy to pound Rubio with criticism that he is "only interested in using this Senate seat to pursue his personal, political ambition."
"Floridians deserve a full-time senator who will serve a full term in office. They deserve assurance from Senator Rubio that he won't just abandon them to run for president in 2020," Murphy, a two-term congressman from Jupiter, said Tuesday in a conference call with state and national media.
I will show up & fight for Floridians for the full 6 years in the U.S. Senate. I have signed the pledge & hope Rubio will do the same #FLSen
Rubio campaign spokeswoman Olivia Perez-Cubas didn't directly respond to Murphy's challenge and instead pivoted to criticizing Murphy for not taking Rubio up on a challenge he first made last week asking Murphy to commit to six debates.
"Patrick Murphy should agree to debate this subject," she said in a statement. "But because he was ranked one of the most ineffective members of Congress, has achieved nothing in four years as a congressman and holds radical liberal views about health care, the economy and national security, he is afraid to agree to multiple debates."
"His privileged upbringing has left him with a sense of entitlement, which is why he is often too busy spending time on his yacht in Nantucket instead of working in Florida," she added.
Murphy said again Tuesday that how many debates he has with Rubio will be contingent on Rubio committing to a full six-year term. Murphy offered that condition as a counter-challenge to Rubio's. The two have agreed to only one debate so far.
"I'm very excited to debate Senator Rubio multiple times," Murphy said. "I think it's a great opportunity to show what a contrast there is between the two of us. ... I'm going to take his challenge seriously, if he commits to serving a full term."
Murphy had previously pledged to debate his primary opponent, fellow U.S. Rep. Alan Grayson -- citing a similar contrast a debate would showcase between them -- but he never did.
*This post has been updated with comment from Rubio's campaign.